CN111347937B

CN111347937B - Heating method of power battery, motor control circuit and vehicle

Info

Publication number: CN111347937B
Application number: CN201811574414.XA
Authority: CN
Inventors: 刘长久; 潘华; 宁荣华; 杨宁; 刘捷宇
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2018-12-21
Filing date: 2018-12-21
Publication date: 2021-12-07
Anticipated expiration: 2038-12-21
Also published as: CN111347937A

Abstract

The application provides a heating method of a power battery, a motor control circuit and a vehicle, wherein the motor control circuit comprises a switch module, a three-phase inverter, a three-phase alternating current motor, an energy storage module and a control module, the control module is connected with a power supply module, the switch module, the three-phase inverter, the three-phase alternating current motor, a part to be heated and the energy storage module, the technical scheme of the application leads N wires out from the connection point of a three-phase coil in the three-phase alternating current motor, so as to form different loops with the power battery, the energy storage module and the three-phase inverter, a heat source is provided through the three-phase coil, the three-phase inverter, the energy storage module and an internal heating device in the three-phase alternating current motor, the heating of the part to be heated is realized through a cooling loop after a heat exchange medium is heated, and the temperature of the part to be heated can be increased without using an engine or adding a heating device, and the heating efficiency is high, and the temperature of the device to be heated is increased quickly.

Description

Heating method of power battery, motor control circuit and vehicle

Technical Field

The application relates to the technical field of electric automobiles, in particular to a heating method of a power battery, a motor control circuit and a vehicle.

Background

In recent years, new energy vehicles are developed vigorously, power batteries based on lithium ions are widely used, and due to the inherent characteristics of the batteries, the charge and discharge capacity of the power batteries is greatly reduced at low temperature, which affects the use of electric vehicles in cold regions.

In order to solve the problem, in the prior art, a battery management system is used for detecting and sending the temperature of a power battery unit, if the temperature is lower than a preset temperature threshold value, a vehicle control unit commands an engine controller to control an engine to rotate at a constant speed at a certain rotating speed through CAN communication, the engine drives a generator to rotate, and the power battery unit is rapidly charged and discharged through the generator to achieve the purpose of preheating a battery pack.

Another technical scheme in the prior art is that when the ambient temperature is low and the power battery needs to be heated, the cooling liquid is pumped out by the water pump from the refrigerating liquid tank and is sent into the liquid cooling plate of the power battery after being heated by the PTC heater, so that the temperature of the liquid cooling plate of the power battery is raised, and then the liquid cooling plate of the power battery heats the power battery, thereby improving the working performance of the power battery under the cold condition. In the technical scheme, a PTC heater is needed, so that the cost is increased, and if the PTC heater is damaged, the secondary cost is increased.

In summary, the prior art has problems that when the power battery is heated in a low temperature state, the battery heating efficiency is low due to the heating of the engine, and the cost is increased due to the heating of the PTC heater.

Disclosure of Invention

The application aims to provide a heating method of a power battery, a motor control circuit and a vehicle, and aims to solve the problems that in the prior art, when the power battery is heated in a low-temperature state, an engine is adopted to heat the power battery, so that the battery heating efficiency is low, and a PTC heater is adopted to heat the power battery, so that the cost is increased.

The present application is achieved in that in a first aspect the present application provides a motor control circuit comprising a switching module, a three-phase inverter, a three-phase ac motor, an energy storage module and a control module, the motor control circuit is connected to a power supply module through the switch module, the first end of the three-phase inverter is connected with the positive pole end of the power supply module, the second end of the three-phase inverter is connected with the negative end of the power supply module, the three-phase coil of the three-phase alternating current motor is connected with the three-phase bridge arm of the three-phase inverter, the first end of the energy storage module is connected with the first switch module and the three-phase inverter, the second end of the energy storage module is connected with a three-phase coil common junction of the three-phase alternating current motor, the control module is connected with the power supply module, the switch module, the three-phase inverter, the three-phase alternating current motor and the energy storage module;

the control module controls the switch module to be conducted and controls the energy storage module to be in a working state, and controls the three-phase inverter to receive the charging process of the energy storage module and the three-phase coil and the discharging process of the energy storage module and the three-phase coil, which are performed alternately by the power supply module, so that the energy storage module, the three-phase inverter and the three-phase alternating current motor heat a heat exchange medium flowing through at least one heat exchange medium pipeline in the energy storage module, the three-phase inverter and the three-phase alternating current motor.

A second aspect of the present application provides a vehicle, further including the motor control circuit of the first aspect, the vehicle further including a driving module and a heat exchange medium pipeline, the heat exchange medium pipeline being disposed on at least one of the power battery and the energy storage module, the three-phase inverter, and the three-phase ac motor, the driving module being connected to the control module;

the control module controls the driving module to drive the heat exchange medium in the heat exchange medium pipeline to flow.

In a third aspect, the present application provides a method for heating a power battery, using the motor control circuit of the first aspect, the method for heating a power battery includes:

when the power battery needs to be heated, the switch module is controlled to be conducted and the energy storage module is controlled to be in a working state;

and controlling the three-phase inverter to receive the charging process of the energy storage module and the three-phase coil and the discharging process of the energy storage module and the three-phase coil, which are performed alternately by the power supply module, so that the energy storage module, the three-phase inverter and the three-phase alternating current motor heat a heat exchange medium flowing through at least one heat exchange medium pipeline in the energy storage module, the three-phase inverter and the three-phase alternating current motor, and further, when the heated heat exchange medium flows through the power battery again, the temperature of the power battery is increased.

The application provides a heating method of a power battery, a motor control circuit and a vehicle, wherein the motor control circuit comprises a switch module, a three-phase inverter, a three-phase alternating current motor, an energy storage module and a control module, the control module is connected with a power supply module, the switch module, the three-phase inverter, the three-phase alternating current motor, a to-be-heated part and the energy storage module, the control module controls the switch module to be switched on and controls the energy storage module to be in a working state when the to-be-heated part needs to be heated, and the power supply module alternately carries out the charging process of the energy storage module and a three-phase coil of the three-phase alternating current motor and the discharging process of the energy storage module and the three-phase coil of the three-phase alternating current motor by controlling the three-phase inverter so as to heat a heat exchange medium flowing through at least one heat exchange medium pipeline in the energy storage module, the three-phase inverter and the three-phase alternating current motor, and the heated heat exchange medium raises the temperature of the part to be heated when flowing through the part to be heated. This application technical scheme three-phase coil's tie point draws forth N line in three-phase alternating current motor, and then with power battery, energy storage module and three-phase inverter constitute different return circuits, through the inside three-phase coil of three-phase alternating current motor, three-phase inverter and energy storage module and inside device that generates heat provide the heat source, the heating of treating the heating device is realized through cooling circuit behind the heating heat transfer medium, need not use the engine or increase heating device just can realize promoting the temperature of treating the heating device, and heating efficiency is high, it is fast to treat the rising of heating device temperature.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a motor control circuit according to an embodiment of the present application;

FIG. 2 is a schematic diagram of another configuration of a motor control circuit according to an embodiment of the present application;

FIG. 3 is a schematic diagram of another configuration of a motor control circuit according to an embodiment of the present application;

FIG. 4 is a schematic diagram of another configuration of a motor control circuit according to an embodiment of the present application;

FIG. 5 is a schematic diagram of another configuration of a motor control circuit according to an embodiment of the present application;

FIG. 6 is a schematic diagram of another configuration of a motor control circuit according to an embodiment of the present application;

FIG. 7 is a schematic diagram of another configuration of a motor control circuit according to an embodiment of the present application;

FIG. 8 is a circuit diagram of the motor control circuit provided in FIG. 7;

FIG. 9 is a current circuit diagram of the motor control circuit provided in FIG. 7;

FIG. 10 is another current circuit diagram of the motor control circuit provided in FIG. 7;

FIG. 11 is another current circuit diagram of the motor control circuit provided in FIG. 7;

FIG. 12 is another circuit diagram of a motor control circuit according to an embodiment of the present application;

FIG. 13 is another circuit diagram of a motor control circuit according to an embodiment of the present application;

FIG. 14 is a schematic illustration of a vehicle according to an embodiment of the present application;

fig. 15 is an internal structural schematic diagram of a three-phase alternating-current motor in a vehicle according to a sixth embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In order to explain the technical means of the present application, the following description will be given by way of specific examples.

The embodiment of the present application provides a motor control circuit, as shown in fig. 1, the motor control circuit includes a switch module 103, a three-phase inverter 102, a three-phase ac motor 101, an energy storage module 105 and a control module 106, the motor control circuit is connected to a power supply module 104 through the switch module 103, a first end of the three-phase inverter 102 is connected to a positive terminal of the power supply module 104, a second end of the three-phase inverter 102 is connected to a negative terminal of the power supply module 104, a three-phase coil of the three-phase ac motor 101 is connected to a three-phase bridge arm of the three-phase inverter 102, a first end of the energy storage module 105 is connected to the switch module 103 and the three-phase inverter 102, a second end of the energy storage module 105 is connected to a three-phase coil common junction of the three-phase ac motor 101, and the control module 106 is connected to the power supply module 104, the switch module 103, the three-phase inverter 102, and the control module 106, The three-phase inverter 102, the three-phase ac motor 101, a member to be heated, and the energy storage module 105.

When the control module 104 detects that the component to be heated needs to be heated, the switch module 103 is controlled to be switched on and the energy storage module 105 is controlled to be in a working state, and the three-phase inverter 102 is controlled to enable the power supply module 104 to alternately perform a charging process of the energy storage module 105 and a three-phase coil of the three-phase alternating current motor 101 and a discharging process of the energy storage module 105 and the three-phase coil of the three-phase alternating current motor 101, so that the energy storage module 105, the three-phase inverter 102 and the three-phase alternating current motor 101 heat a heat exchange medium flowing through the energy storage module 105, the three-phase inverter 102 and at least one heat exchange medium pipeline of the three-phase alternating current motor 101, and the heated heat exchange medium is heated when flowing through the component to be heated, so that the temperature of the component to be heated is increased.

The power supply module 104 may be a power supply module inside the vehicle or a power supply module outside the vehicle, for example, the power supply provided by the power supply module 104 may be direct current provided by a direct current charging pile, direct current output by a single-phase or three-phase alternating current charging pile after rectification, electric energy generated by a fuel cell, a power supply form such as a power supply form in which a range extender such as an engine rotates to drive a generator to generate electricity, direct current rectified by a generator controller, and the like, or a power supply provided by a power battery inside the vehicle; the three-phase inverter 102 comprises six power switch units, wherein the power switch units can be transistor, IGBT, MOS tube and other device types, two power switch units form a phase bridge arm, the phase bridge arm is formed by the two power switch units, a connection point of the two power switch units in each phase bridge arm is connected with a phase coil in the three-phase alternating current motor 101, the three-phase alternating current motor 101 comprises a three-phase coil, the three-phase coil is connected with one point, the three-phase alternating current motor 101 can be a permanent magnet synchronous motor or an asynchronous motor, the three-phase alternating current motor 101 is of a three-phase four-wire system, namely N wires are led out from the connection point of the three-phase coil, and the N wires and the energy storage module 105 are connected in series to form a connection circuit; the switch module 103 is used for enabling the power supply module 104 to be connected to a circuit for charging or disconnected from the circuit, and the power supply module 104 can be connected to a charging loop when the power supply module 104 is required to be discharged by controlling the switch module 103; the energy storage module 105 is configured to store electric energy output by the power battery 120 or the external power module 107, and the energy storage module 105 may include an energy storage device 111 such as an inductor; the control module 106 CAN acquire the voltage, current and temperature of the power battery 120 and the phase current of the three-phase alternating current motor 101, the control module 106 CAN include a vehicle control unit, a control circuit of a motor controller and a BMS battery manager circuit, which are connected by a CAN line, and different modules in the control module 106 control the conduction and the turn-off of power switches in the three-phase inverter 102 according to the acquired information to realize the conduction of different current loops; the component to be heated may be located near the energy storage module 105, the three-phase inverter 102, and the three-phase ac motor 101, for example, the component to be heated and at least one of the energy storage module 105, the three-phase inverter 102, and the three-phase ac motor 101 are located in the same compartment, or heat of at least one of the energy storage module 105, the three-phase inverter 102, and the three-phase ac motor 101 may be transferred to the component to be heated through a heat exchange medium, for example, heat exchange medium pipelines are provided on the energy storage module 105, the three-phase inverter 102, and the three-phase ac motor 101, and a heat exchange medium flows through the heat exchange medium pipelines, so as to adjust the temperature of the component to be heated by adjusting the temperature of the heat exchange medium pipelines.

This application embodiment draws forth N line in three-phase AC motor, and then with power module, energy storage module and three-phase inverter constitute different return circuits, provide the heat source through the inside three-phase coil of three-phase AC motor, three-phase inverter and energy storage module and inside device that generates heat thereof, the heating of treating the heater block is realized through former cooling circuit behind the heating heat transfer medium, need not use the engine or increase heating device just can realize promoting the temperature of treating the heater block, and heating efficiency is high, it is fast to treat the heater block temperature rising.

In a specific embodiment, the component to be heated and the power supply module are the same component, such as a power battery. Like this, not only at the in-process that forms the circuit loop, power battery can make self temperature rise because of the internal resistance, and, can also be through the produced heat transfer of the motor control circuit in this application for power battery, promptly: the motor control circuit in this application both can be used for charging power battery, also can be used for power battery to supply power for three-phase alternating current motor in order to drive the wheel rotation, can also be used to provide the heat source for the power battery that needs the heating.

As a first embodiment, the power supply module 104, the switching module 103, the energy storage module 105, the three-phase ac motor 101, and the three-phase inverter 102 form a first charging circuit, and the three-phase ac motor 101, the three-phase inverter 102, and the energy storage module 105 form a discharging circuit; the control module 106 controls the three-phase inverter 102 to alternately conduct the first charging circuit and the discharging circuit, so that the charging process of the power battery 120 on the energy storage module 105 and the three-phase coil and the discharging process of the energy storage module 105 and the three-phase coil are alternately performed.

Wherein, the first charging loop forms an inductive energy storage loop, the control module 106 controls the switch module 103 to be conducted and controls the power switch unit in the three-phase inverter 102 to conduct the first charging loop for a period of time, then the control module 106 controls the discharge loop to be conducted, the energy storage module 105 and the three-phase ac motor 101 both have current outputs, so that the discharge loop forms a current follow current loop, the control module 106 can output PWM signals to control the three-phase inverter 102 to realize the alternate conduction of the first charging loop and the discharge loop, so that the energy storage module 105, the three-phase inverter 102 and the three-phase ac motor 101 are in the working state, in this embodiment, the energy storage module, the three-phase inverter and the three-phase ac motor heat the heat exchange medium of at least one heat exchange medium pipeline in the energy storage module, the three-phase inverter and the three-phase ac motor by controlling the three-phase inverter to make the first charging loop and the discharge loop alternately conducted, and when the heated heat exchange medium flows through the part to be heated, the temperature of the part to be heated is increased.

As an embodiment, as shown in fig. 2, the power supply module 104 and the device to be heated are both power batteries 120, and the switch module 103 is a first switch module 121; because of the inherent characteristics of the battery, the charge and discharge capacity of the power battery 120 is greatly reduced in the low-temperature state, which may affect the use of the new energy vehicle in the cold region, and in order to make the power battery 120 work normally, it is necessary to raise the temperature of the power battery 120 when the temperature of the power battery 120 is too low, therefore, the temperature of the power battery 120 is obtained through the control module 106, the battery manager may be used to obtain the temperature of the power battery 120, the temperature of the power battery 120 is compared with the preset temperature value to determine whether the power battery 120 is in the low-temperature state, when it is detected that the temperature of the power battery 120 is lower than the preset temperature value, the temperature of the power battery 120 may be raised by raising the temperature of the heat exchange medium flowing through the power battery 120, because the energy storage module 105, the three-phase inverter 102 and the three-phase alternating current motor 101 all generate heat during the work, therefore, the energy storage module 105, the three-phase inverter 102 and the three-phase ac motor 101 can be controlled to heat the heat exchange medium flowing through the power battery 120, the heat exchange medium can be heated by charging the power battery 120 to the energy storage module 105 and the three-phase coil, discharging is performed after the energy storage module 105 and the three-phase coil finish storing electric energy, heat can be generated in the process of charging and discharging the energy storage module 105 and the three-phase coil, the cooling liquid can be heated,

further, as shown in fig. 3, the energy storage module 105 includes an energy storage device 111 and a first switching device 110, the first switching device 110 is connected to the three-phase ac motor 101, the control module 106 and the energy storage device 111, the energy storage device 111 is connected to the three-phase inverter 102 and the first switching module 121, and the power battery 120, the first switching module 121, the energy storage device 111, the first switching device 110, the three-phase ac motor 101 and the three-phase inverter 102 form a first charging loop; the control module 106 controls the first switching device 110 to be conductive and alternately conducts the first charging circuit and the discharging circuit by controlling the three-phase inverter 102.

The first end of the energy storage module 105 is connected to the first end of the three-phase inverter 102, or the first end of the energy storage module 105 is connected to the second end of the three-phase inverter 102, and the control module controls the first switching device to be turned on to control the energy storage module to be in the working state.

The energy storage device 111 may be an inductor, and by providing the first switching device 110, the control module 106 may control the energy storage device 111 to be connected to and disconnected from the first charging loop or the first discharging loop, so as to control the operating state of the energy storage device 111.

Furthermore, as shown in fig. 4, the energy storage module 105 further includes a sixth switching device 112, a control terminal of the sixth switching device 112 is connected to the control module 106, a connection terminal of the sixth switching device 112 is connected to the energy storage device 111, a first gate terminal of the sixth switching device 112 is connected to the first terminal of the three-phase inverter 102 and the first terminal of the first switching module 121, a second gate terminal of the sixth switching device 112 is connected to the second terminal of the three-phase inverter 102 and the second terminal of the first switching module 121, the control module 106 controls the connection terminal of the sixth switching device 112 to alternately gate the first gate terminal and the second gate terminal, the control module 106 controls the connection terminal of the sixth switching device 112 to be connected to the first gate terminal or the second gate terminal, and the control module 106 further controls the first switching device 110 to be turned on to control the energy storage module to be in the working state.

The sixth switching device 112 is a single-pole double-throw switch, a connection end of the sixth switching device 112 may be connected to the first gating end or the second gating end according to a signal output by the control module 106, when the single-pole double-throw switch is connected to the first gating end, the energy storage module 105 is connected to the first end of the three-phase inverter 102 and the first end of the first switching module 121, at this time, a current in the three-phase inverter 102 flows through a power switch in a lower bridge arm and a freewheeling diode in an upper bridge arm, only half of power devices of each conducted power switching unit of the three-phase inverter 102 flow the current, and the other half of the power switching units do not flow the current; when the single-pole double-throw switch is connected with the second gating end, the energy storage module 105 is connected with the second end of the three-phase inverter 102 and the second end of the first switch module 121, at this time, the current in the three-phase inverter 102 flows through the power switch in the upper bridge arm and the diode in the lower bridge arm, only half of the power devices of each conducted power switch unit of the three-phase inverter 102 flow the current, and the other half of the power devices do not flow the current; in the embodiment, by arranging the sixth switching device, when the upper and lower contacts of the sixth switching device are controlled to be periodically connected, the first half period is connected with the first gating end, and the second half period is connected with the second gating end, so that the power devices in the upper and lower bridge arms of the three-phase inverter can be electrified and heated in turn, and further the three-phase inverter generates heat in a rotation period and tends to be balanced.

As a second embodiment, as shown in fig. 4, the power supply module is an external power supply module 107, the switching module is a second switching module 108, the motor control circuit still includes a first switching module 121 and a power battery 120, the external power supply module 107 is connected to the control module 106 and the second switching module 108, and the second switching module 108 is connected to the energy storage module 105, the three-phase inverter 102 and the control module 106; when the control module 106 detects that the temperature of the power battery 120 is lower than a preset temperature value and detects that the external power module 107 is connected, the control module controls the first switch module 121 to be turned off and the second switch module 108 to be turned on, and controls the three-phase inverter 102 to enable the external power module 107 to alternately perform a charging process of the energy storage module 105 and the three-phase coil and a discharging process of the energy storage module 105 and the three-phase coil, so that the energy storage module 105, the three-phase inverter 102 and the three-phase alternating current motor 101 heat the coolant flowing through the power battery 120.

The control module 106 detects whether the external power module 107 is connected or not when detecting that the temperature of the power battery 120 is lower than a preset temperature value, when the external power module 107 is connected, the energy storage module 105 and the three-phase coil are charged through the external power module 107, when the energy storage module 105 and the three-phase coil store electric energy, the energy storage module and the three-phase coil discharge, and when the energy storage module 105 and the three-phase coil generate heat in the charging and discharging processes, the cooling liquid can be heated. The temperature of the power battery can be increased without using an engine or adding a heating device, the heating efficiency is high, and the temperature of the power battery is increased quickly.

Further, as shown in fig. 5, the external power module 107, the second switching module 108, the energy storage module 105, the three-phase ac motor 101 and the three-phase inverter 102 form a second charging circuit, and the three-phase ac motor 101, the three-phase inverter 102 and the energy storage module 105 form a discharging circuit; the control module 106 controls the three-phase inverter 102 to alternately conduct the second charging circuit and the discharging circuit, so that the charging process of the power battery 120 on the energy storage module 105 and the three-phase coil and the discharging process of the energy storage module 105 and the three-phase coil are alternately performed.

Wherein, the second charging loop forms an inductive energy storage loop, the control module 106 controls the second switching module 108 to conduct and controls the power switching unit in the three-phase inverter 102 to conduct the second charging loop for a period of time, then the control module 106 controls the discharging loop to conduct, the energy storage unit and the three-phase ac motor 101 both have current outputs, so that the discharging loop forms a current follow current loop, the control module 106 can output PWM signals to control the three-phase inverter 102 to realize the alternate conduction of the second charging loop and the discharging loop, so that the energy storage module 105, the three-phase inverter 102 and the three-phase ac motor 101 are in working states, in this embodiment, by controlling the three-phase inverter 102 to alternately conduct the second charging circuit and the discharging circuit, the energy storage module 105, the three-phase inverter 102 and the three-phase ac motor 101 are enabled to heat the heat exchange medium flowing through the power battery 120.

Further, as shown in fig. 6, the energy storage module 105 includes an energy storage device 111 and a first switching device 110, the first switching device 110 is connected to the three-phase ac motor 101, the control module 106 and the energy storage device 111, and the energy storage device 111 is connected to the three-phase inverter 102, the first switching module 121 and the second switching module 108; the external power supply module 107, the second switching module 108, the energy storage device 111, the first switching device 110, the three-phase alternating current motor 101 and the three-phase inverter 102 form a second charging loop, and the three-phase alternating current motor 101, the three-phase inverter 102, the energy storage device 111 and the first switching device 110 form a discharging loop; the control module 106 controls the first switching device 110 to be turned on and alternately turns on the charging circuit and the discharging circuit by controlling the three-phase inverter 102.

Further, as shown in fig. 7, the energy storage module 105 further includes a sixth switching device 112, a control terminal of the sixth switching device 112 is connected to the control module 106, a connection terminal of the sixth switching device 112 is connected to the energy storage device 111, a first gate terminal of the sixth switching device 112 is connected to the first terminal of the three-phase inverter 102, the first terminal of the first switching module 121, and the first terminal of the second switching module 108, a second gate terminal of the sixth switching device 112 is connected to the second terminal of the three-phase inverter 102, the second terminal of the first switching module 121, and the second terminal of the second switching module 108, and the control module 106 controls the connection terminal of the sixth switching device 112 to be connected to the first gate terminal or the second gate terminal.

In the embodiment, by arranging the sixth switching device, when the external power supply is connected to the circuit and the upper and lower contacts of the sixth switching device are controlled to be periodically connected, the first half period is connected with the first gating end, and the second half period is connected with the second gating end, so that the power devices in the upper and lower bridge arms of the three-phase inverter can be electrified and heated in turn, and the three-phase inverter can be heated to be balanced in a turn period.

For the three-phase inverter 102, as an embodiment, the three-phase inverter 102 includes three-phase bridge arms, each phase of bridge arm includes two power switch units connected in series, and three-phase coils of the three-phase ac motor 101 are respectively connected to connection points of the two power switch units of each phase of bridge arm; the control module 106 controls two power switch units on at least one phase of the bridge arm of the three-phase inverter 102 to be alternately turned on, so that the charging process of the power battery 120 or the external power supply module 107 on the three-phase coil of the three-phase alternating current motor 101 and the energy storage module 105 and the discharging process of the three-phase coil of the three-phase alternating current motor 101 and the energy storage module 105 on the power battery 120 are alternately performed.

The three-phase inverter 102 may be controlled to switch different bridge arms to conduct according to needs to realize the heating function of the power battery, for example, the bridge arm controlled to conduct may be any one phase bridge arm or any two phase bridge arm in the three-phase bridge arms or may be 7 switching heating methods in total with the three-phase bridge arm.

Further, the control module 106 obtains the bridge arm conduction number of the three-phase inverter 102 according to the power to be heated of the power battery 120, and controls a corresponding number of bridge arms to operate according to the bridge arm conduction number.

The number of the bridge arms to be connected can be selected according to the power to be heated of the power battery 120, the power to be heated of the power battery 120 can be obtained through a battery manager according to the current state of the power battery, for example, for low-power heating, any phase of bridge arms can be selected to work for heating, for medium-power heating, any two phases of bridge arms can be selected to work for heating, and for high-power heating, three phases of bridge arms can be selected to work simultaneously for heating.

As a first embodiment, when detecting that the power to be heated of the power battery 120 is smaller than a first preset power, the control module 106 determines that the number of the bridge arms of the three-phase inverter 102 is 1, and controls any one of the three-phase bridge arms to operate or the three-phase bridge arms to operate by switching alternately.

When the control module 106 detects that the power to be heated of the power battery 120 is small, 1 of the three-phase bridge arms is controlled to be conducted to meet the charging requirement, and assuming that the three-phase bridge arms include an a-phase bridge arm, a B-phase bridge arm and a C-phase bridge arm, any one of the three-phase bridge arms can be controlled to work all the time, or the three-phase bridge arms can be controlled to switch in turn.

As a second implementation manner, when detecting that the power to be heated of the power battery 120 is not less than the first preset power and less than the second preset power, the control module 106 determines that the number of bridge arms of the three-phase inverter 102 that are connected is 2, and controls any 2-phase bridge arm of the three-phase bridge arms to operate or three two-phase bridge arms of the three-phase bridge arms to operate sequentially, where the three-phase inverter includes an a-phase bridge arm, a B-phase bridge arm, and a C-phase bridge arm, the first two-phase bridge arm includes an a-phase bridge arm and a B-phase bridge arm, the second two-phase bridge arm includes an a-phase bridge arm and a C-phase bridge arm, and the first three-phase bridge arm includes a B-phase bridge arm and a C-phase bridge arm.

When the control module 106 detects that the power to be heated of the power battery 120 is not less than a first preset power and less than a second preset power, 2 bridge arms in the three-phase bridge arms are controlled to be conducted to meet the charging requirement, any two-phase bridge arm in the three-phase bridge arms can be controlled to work all the time, and three two-phase bridge arms in the three-phase bridge arms can be controlled to switch over to work in turn, for example, an a-phase bridge arm and a B-phase bridge arm can be regarded as a first group of two-phase bridge arms, an a-phase bridge arm and a C-phase bridge arm can be regarded as a second group of two-phase bridge arms, a B-phase bridge arm and a C-phase bridge arm can be regarded as a third group of two-phase bridge arms, namely, the first group of two-phase bridge arms are controlled to work, the C-phase bridge arms do not work, the second group of two-phase bridge arms are controlled to work, the third group of two-phase bridge arms do not work, and the three groups of two-phase bridge arms are controlled to switch over to work in turn over in turn, the three-phase inverter 102 and the three-phase coil heat generation balance can be realized.

In the second embodiment, the phases of the PWM control signals sent by the control module 106 to the two-phase arms are different by 180 degrees.

When only two-phase bridge arms work, the two-phase control signals respectively sent to the two-phase bridge arms have a phase difference of about 180 degrees, so that positive and negative ripples of two-phase coils are mutually superposed and mutually offset, and the total ripples can be greatly reduced.

As a third embodiment, when detecting that the power to be heated of the power battery 120 is not less than the second preset power, the control module 106 determines that the number of bridge arms of the three-phase inverter 102 is 3, and controls the three-phase bridge arms to operate simultaneously.

When the control module 106 detects that the power to be heated of the power battery 120 is large, 3 of the three-phase bridge arms are controlled to be conducted to meet the heating requirement, the three-phase bridge arms of the three-phase bridge arms are controlled to work simultaneously, and the currents output by the three-phase bridge arms are balanced due to the theoretical balance of three-phase loops, so that the heating balance of the three-phase inverter 102 and the three-phase coil is realized.

In the third embodiment, further, the control module 106 sends PWM control signals with the same phase to the three-phase bridge arm;

or the control module 106 sends PWM control signals with different phases to the three-phase bridge arms, where the phase of the PWM control signal of one phase of bridge arm differs from the phase of the PWM control signal of the other two phase of bridge arm by 60 degrees and-60 degrees, respectively.

In order to reduce the total ripple of the charging circuit, a phase-staggered control mode of switching of the inverter can be carried out, when the three-phase bridge arms are controlled to work, three-phase control signals output to the three-phase bridge arms are staggered by about 60 degrees of phase, and thus positive and negative ripples of the three-phase coils are mutually superposed and mutually offset, so that the total ripple can be greatly reduced. The synchronous control mode can also be adopted, namely the three-phase bridge arm power switches are simultaneously controlled to be synchronously switched on and switched off, so that the three-phase current is simultaneously increased when being switched on and reduced when being switched off, the three-phase current is more equal at any moment, the three-phase synthetic magnetomotive force is more zero, the stator magnetic field is more zero, and the motor basically has no torque.

In the third embodiment, further, the control module 106 obtains the current value of each phase of the bridge arm when the three phase bridge arms are simultaneously operated, and adjusts the control signal of each phase of the bridge arm to make the average current value of the three phase bridge arms be within the preset current range.

In some actual circuits, the three-phase ac motor 101 and the three-phase circuit of the motor controller are not always identical, so that the three-phase currents are not always equal during open-loop control, and the current difference may become larger and larger over a long period of time, so that independent closed-loop control of the three-phase currents is required to control the average value of the three-phase currents to a preset precision range of the equilibrium value.

In the third embodiment, further, when the three-phase bridge arms operate simultaneously, the control module 106 obtains the current value of each phase of bridge arm, and adjusts the control signal of each phase of bridge arm to make the current values of the three-phase bridge arms not identical and make the current difference value of each two-phase bridge arm smaller than the preset current threshold value.

When the three-phase current independent closed-loop control is carried out, one phase of current is controlled to be slightly larger than the other two phases of current, the other two phases of current can be controlled to be two phases of current with the same average value or current with the same average value, so that a magnetic field generated by the three-phase current is not zero but small, and the motor torque is not zero but small, so that a motor rotating shaft can output a small torque on a vehicle, gear gaps are meshed, the jitter and noise caused by torque fluctuation are reduced, and the current size and the output torque size can be determined according to the actual situation requirement by controlling the three-phase current size.

As an embodiment, the alternating conduction of the charging and discharging circuits may be controlled in the following manner: the control module 106 outputs a PWM control signal to the three-phase inverter 102 to alternately turn on the charging circuit and the discharging circuit, and obtains the power to be heated of the power battery 120, calculates the actual heating power according to the product of the bus voltage and the bus current input by the three-phase inverter, compares the actual power to the power battery 120 with the power to be heated, and adjusts the duty ratio of the PWM control signal according to the comparison result to adjust the current output to the power battery 120.

The control module 106 obtains the power to be heated according to the current state of the power battery, compares the actual heating power with the power to be heated when obtaining the actual heating power, adjusts and increases the PWM on-duty ratio when the actual heating power is smaller than the power to be heated, and adjusts and decreases the PWM on-duty ratio when the actual heating power is larger than the power to be heated until the charging power is satisfied.

For the three-phase inverter 102, specifically, the three-phase inverter 102 includes a first power switch unit, a second power switch unit, a third power switch unit, a fourth power switch unit, a fifth power switch unit, and a sixth power switch unit, a control end of each power switch unit is connected to the control module 106, input ends of the first power switch unit, the third power switch unit, and the fifth power switch unit are connected in common and connected to the energy storage module, output ends of the second power switch unit, the fourth power switch unit, and the sixth power switch unit are connected in common and connected to a negative electrode of the power battery 120, a first phase coil of the three-phase ac motor 101 is connected to an output end of the first power switch unit and an input end of the fourth power switch unit, a second phase coil of the three-phase ac motor 101 is connected to an output end of the third power switch unit and an input end of the sixth power switch unit, a third-phase coil of the three-phase ac motor 101 is connected to the output terminal of the fifth power switching unit and the input terminal of the second power switching unit.

The first power switch unit and the fourth power switch unit in the three-phase inverter 102 form an a-phase bridge arm, the third power switch unit and the sixth power switch unit form a B-phase bridge arm, the fifth power switch unit and the second power switch unit form a C-phase bridge arm, and the control mode for the three-phase inverter 102 may be any one or a combination of the following: if any one or any two of A, B, C three-phase bridge arms and three bridge arms can be realized, 7 control heating modes are realized, and the method is flexible and simple. The switching of the bridge arms can be beneficial to realizing the large, medium and small selection of heating power, for example, for small-power heating, any phase of bridge arm power switches can be selected for control, and three-phase bridge arms can be switched in turn, for example, an A-phase bridge arm works alone first, a first power switch unit and a fourth power switch unit are controlled to heat for a period of time, then a B-phase bridge arm works alone, a third power switch unit and a sixth power switch unit are controlled to heat for the same period of time, then a C-phase bridge arm works alone, a fifth power switch unit and a second power switch unit are controlled to heat for the same period of time, and then the A-phase bridge arm works, so that the three-phase inverter 102 and a three-phase coil are circulated to be electrified and heated in turn, and three-phase heating is more balanced; for medium-power heating, any two-phase bridge arm power switches can be selected for control, and three-phase bridge arms can be switched in turn, for example, an AB-phase bridge arm works first, a first power switch unit, a fourth power switch unit, a third power switch unit and a sixth power switch unit are controlled to heat for a period of time, then a BC-phase bridge arm works, a third power switch unit, a sixth power switch unit, a fifth power switch unit and a second power switch unit are controlled to heat for the same time, then a CA-phase bridge arm works, a fifth power switch unit, a second power switch unit, a first power switch unit and a fourth power switch unit are controlled to heat for the same time, and then the CA-phase bridge arm works, and the steps are repeated to realize that the three-phase inverter 102 and a three-phase coil heat more evenly; for high-power heating, a three-phase bridge arm power switch can be selected for control, three-phase currents are balanced due to the fact that a three-phase loop is balanced theoretically, the three-phase currents are basically direct currents and are balanced by the three-phase inverter 102 and a three-phase coil, average values of the three-phase currents are basically consistent, three-phase synthetic magnetomotive force in the motor is basically zero due to the fact that three-phase windings are symmetrical, a stator magnetic field is basically zero, the motor basically does not generate torque, and stress of a transmission system is greatly reduced.

Another embodiment of the present application provides a method for heating a power battery, where based on the above motor control circuit, the method for heating a power battery includes:

and controlling the three-phase inverter to receive the charging process of the energy storage module and the three-phase coil and the discharging process of the energy storage module and the three-phase coil, which are alternately performed by the power supply module, so that the energy storage module, the three-phase inverter and the three-phase alternating current motor heat a heat exchange medium flowing through at least one heat exchange medium pipeline in the energy storage module, the three-phase inverter and the three-phase alternating current motor, and further, when the heated heat exchange medium flows through the part to be heated, the temperature of the part to be heated is increased.

Further, the motor control circuit further comprises an external power module and a second switch module;

the heating method of the motor control circuit further includes:

when the temperature of the power battery is detected to be lower than a preset temperature value and the external power supply module is detected to be connected, the first switch module is controlled to be switched off and the second switch module is controlled to be switched on;

and controlling the three-phase inverter to enable the external power supply module to alternately perform a charging process on the energy storage module and the three-phase coil and a discharging process on the energy storage module and the three-phase coil, so that the energy storage module, the three-phase inverter and the three-phase alternating current motor heat the cooling liquid flowing through the power battery.

The technical scheme of the present application is specifically described below by a specific circuit structure:

fig. 8 is a circuit diagram of an example of a motor control circuit of the present application, for convenience of description, the upper diagram omits other electrical devices, and only considers a power battery 120, a three-phase inverter 102, and a three-phase ac motor 101, a first switch module 121 includes a switch K2 and a switch K3, a second switch module 108 includes a switch K4 and a switch K5, a capacitor C1 is connected in parallel to two ends of an external power module 107, an energy storage module 105 includes an inductor L and a switch K1, the power battery 120 is connected in parallel to a bus capacitor C, a first power switch unit in the three-phase inverter 102 includes a first upper bridge arm VT1 and a first upper bridge diode 1, a second power switch unit includes a second lower bridge arm VT2 and a second lower bridge diode VT2, a third power switch unit includes a third upper bridge arm VT3 and a third upper bridge diode VD3, a fourth power switch unit includes a fourth lower bridge arm 4 and a fourth lower bridge diode VD4, the fifth power switch unit includes a fifth upper bridge arm VT5 and a fifth upper bridge diode VD5, the sixth power switch unit includes a sixth lower bridge arm VT6 and a sixth lower bridge diode VD6, the three-phase ac motor 101 is a three-phase four-wire system, and may be a permanent magnet synchronous motor or an asynchronous motor, an N wire is led out from a connection midpoint of three-phase coils, and is connected with a switch K1, three-phase coils of the motor are respectively connected with the upper and lower bridge arms A, B, C of the three-phase inverter 102, and the control step of the control module 106 specifically includes:

step 1, when the whole vehicle is powered on, the whole vehicle controller receives a state signal (for example, the state signal can be determined through gear information and a vehicle speed signal) of a three-phase alternating current motor and a temperature signal of a power battery 120 sent by a battery manager.

And 2, detecting that the current state signal of the three-phase alternating current motor is in a non-driving state by the vehicle control unit (for example, the state signal can be determined by whether the gear is in a P gear and the vehicle speed is zero).

And 3, if not, exiting the motor heating program.

And 4, if so, judging whether the temperature of the power battery 120 is lower than a set threshold value.

And 5, if not, exiting the motor heating program.

Step 6, if yes, the vehicle control unit sends a battery heating instruction to the battery manager and the motor controller;

step 7, as shown in fig. 9, the battery manager controls the switches K1, K2, and K3 to be turned on, so that the power battery 120 discharges and is used for heating, the motor controller first sends PWM control signals to the three-phase inverter 102, and in the on-period of each PWM control signal cycle, the motor controller controls the upper bridge power switch of the three-phase inverter 102 to be turned off, and controls the lower bridge power switch to be turned on, the power battery 120, the inductor L, the switch K1, the three-phase ac motor 101, and the lower bridge power switches (the second lower bridge arm VT2, the fourth lower bridge arm VT4, and the sixth lower bridge arm VT6) form a first charging loop, and the power battery 120 stores energy for the three-phase coil and the inductor L of the three-phase ac motor 101.

Step 8, as shown in fig. 10, the motor controller controls the lower bridge power switch of the three-phase inverter 102 to be turned off during the PWM period, the upper bridge power switch may be turned off all the time (at this time, the power battery 120 may also be turned on), the three-phase coil of the three-phase ac motor 101, the upper bridge power switch (the first upper bridge diode VD1, the third upper bridge diode VD3, and the fifth upper bridge diode VD5), the inductor L, and the switch K1 form a discharging loop, the three-phase coil of the three-phase ac motor 101 and the inductor L discharge electricity, and form an inductor current freewheeling loop with the upper bridge freewheeling diode.

And 9, receiving the bus voltage and bus current data input by the three-phase inverter by the motor controller, calculating output power, regarding the output power as battery heating power, comparing the calculated heating power with heating instruction power sent by the battery manager, increasing the PWM duty ratio and increasing the bus current if the calculated heating power is low, and reducing the PWM duty ratio and the bus current if the calculated heating power is high until the heating power reaches the vicinity of the heating instruction power.

And step 10, the vehicle control unit circularly detects a state signal (such as determined by gear information and a vehicle speed signal) of the three-phase alternating current motor and the temperature of the power battery, the steps are repeated when the conditions are met, the heating program is quitted when the conditions are not met, the motor controls and controls the upper bridge and the lower bridge of the three-phase inverter 102 to be completely switched off, the battery manager controls the switch K1 to be switched off, and the switch K4 and the switch K5 can be also switched off if the charging is not needed.

When the circuit is connected to the external power module 107, the control module 106 controls the external power module 107 to heat, and the control step of the control module 106 specifically includes:

And 3, if not, exiting the motor heating program.

And 5, if not, exiting the motor heating program.

step 7, as shown in fig. 11, the battery manager controls the switches K1, K4, and K5 to be turned on, so that the external power module 107 discharges electricity for heating, the motor controller sends PWM control signals to the three-phase inverter 102, and in the on-period of each PWM control signal cycle, the motor controller controls the upper bridge power switch of the three-phase inverter 102 to be turned off, and controls the lower bridge power switch to be turned on, the external power module 107, the inductor L, the switch K1, the three-phase ac motor 101, and the lower bridge power switches (the second lower bridge arm VT2, the fourth lower bridge arm VT4, and the sixth lower bridge arm VT6) form a second charging loop, and the external power module 107 stores energy for the three-phase coil and the inductor L of the motor.

Step 8, as shown in fig. 10, the motor controller controls the lower bridge power switch of the three-phase inverter 102 to be turned off during the PWM period, the upper bridge power switch may be turned off all the time (at this time, the power battery 120 may also be turned on), the discharge path of the power battery 120 is turned off, the three-phase coil of the motor, the upper bridge power switch (the first upper bridge diode VD1, the third upper bridge diode VD3, and the fifth upper bridge diode VD5), the inductor L, and the switch K1 form a discharge loop, the three-phase coil of the motor and the inductor L discharge electricity, and form an inductor current freewheeling loop with the upper bridge freewheeling diode.

And step 10, the vehicle control unit circularly detects the state signals of the three-phase alternating current motor (such as the state signals can be determined through gear information and vehicle speed signals) and the temperature of the power battery 120, the steps are repeated when the conditions are met, the heating program is quitted when the conditions are not met, the motor controls and controls the three-phase inverter 102 to completely switch off the upper bridge and the lower bridge, the battery manager controls the switch K1 to be switched off, and the switch K4 and the switch K5 can also be switched off if the charging is not needed.

Fig. 12 is a circuit diagram of another example of the motor control circuit of the present application, in which one end of an inductor L1 is connected to the negative electrode of a three-phase inverter 102, and all the above heating functions can also be realized, and this circuit topology control needs to be addressed at two points, first, depending on whether the power battery is used for discharge heating or the external power module is used for power supply heating, the control of switches K1, K2, K3, K4, and K5 is the same as the control of the inductor L connected to the positive electrode of the power battery in the above circuit, and second, the difference is the control of the power switch of the three-phase inverter 102, and is just opposite to the control of the inductor L connected to the positive electrode of the power battery in the above circuit, when the inductor L connected to the positive electrode of the power battery, the PWM control is that the lower bridge power switch is turned on, the upper bridge power switch can be turned off all the time, and when the inductor L connected to the negative electrode of the power battery, the PWM control is turned on the upper bridge power switch is turned on, the lower bridge power switch can be turned off the lower bridge power switch all the time, that is, the motor controller controls the upper bridge power switch of the three-phase inverter 102 to be turned on and the lower bridge power switch to be turned off during the PWM period, and the motor controller controls the upper bridge power switch of the three-phase inverter 102 to be turned off and the lower bridge power switch to be turned off all the time (at this time, the upper bridge power switch and the lower bridge power switch may also be turned on) during the PWM period. Besides, other functions such as A, B, C selection of any three-phase arm or any two arms, and 7 control heating modes of three arms, and current control modes such as staggered phase of 60 degrees or 180 degrees, two-phase and three-phase synchronous control, or two-phase and three-phase independent control can also realize the same effect of battery heating function when the connecting circuit is connected with the positive pole of the bus.

Fig. 13 is a circuit diagram of another example of the motor control circuit of the present application, and one end of the inductor L1 may also be connected to the positive electrode or the negative electrode of the three-phase inverter 102 through a single-pole double-throw switch K6, so as to achieve all the above-mentioned heating functions. When the single-pole double-throw switch is connected to the contact 1, one end of the inductor L1 is connected to the positive electrode of the three-phase inverter 102, and all heating control methods are controlled in the manner that the connection circuit is connected with the positive electrode of the bus; when the single-pole double-throw switch is connected to the contact 2, one end of the inductor L1 is connected to the negative pole of the three-phase inverter 102, and all heating control methods are controlled in the manner described above for connecting the negative pole of the bus. When the connection circuit is connected with the positive pole of the bus, for the three-phase inverter 102, current only flows in the lower bridge power switch and the upper bridge diode, only half of the power devices of the three-phase inverter 102 flow current, and the other half of the power devices do not flow current; when the connection circuit is connected with the negative pole of the bus, for the three-phase inverter 102, current only flows through the upper bridge power switch and the lower bridge diode, only half of the power devices of the three-phase inverter 102 flow current, and the other half of the power devices do not flow current. If the periodic connection control of the upper contact and the lower contact of the single-pole double-throw switch is adopted, the contact 1 in the first half period and the contact 2 in the second half period can enable the power devices of the three-phase inverter 102 to be electrified and heated in turn, and the heat generated by the inverter in a rotation period tends to be balanced.

Another embodiment of the present application provides a vehicle, further including the above-mentioned motor control circuit, the vehicle further including a driving module and a heat exchange medium pipeline, the heat exchange medium pipeline is disposed on at least one of the power battery and the energy storage module, the three-phase inverter, and the three-phase ac motor, and the driving module is connected to the control module;

Specifically, as shown in fig. 14, the control module includes a vehicle control unit 301, a battery manager 302, a first motor controller 305, and a second motor controller 303, the vehicle control unit 301 is connected to the battery manager 302, the first motor controller 305, and the second motor controller 303 through a CAN bus, the dc charging pile is electrically connected to the first three-phase ac motor 306 through a connection line 307, the dc charging pile is electrically connected to the second three-phase ac motor 304 through a connection line 310, the power battery is electrically connected to the first motor controller 305 and the second motor controller 303, the cooling liquid tank 308, the water pump 309, the first three-phase ac motor 306, the first motor controller 305, the second three-phase ac motor 304, the second motor controller, and the power battery form a cooling liquid pipeline, the battery manager 302 is configured to collect power battery information including voltage, current, temperature, and the like, the motor controller is used for controlling power switches of an upper bridge and a lower bridge of the three-phase inverter and collecting three-phase current, and the vehicle controller is used for managing the operation of a whole vehicle and other controller equipment on the vehicle. The battery manager 302 and the motor controller are communicated with the vehicle control unit 301 through a CAN (controller area network) line, when the vehicle control unit 301 detects that the power battery needs to be heated, the water pump 309 is controlled to pump cooling liquid out of the cooling liquid tank 308, the cooling liquid flows through the power battery through the first three-phase alternating current motor 306, the first motor controller 305, the second three-phase alternating current motor 304 and the second motor controller 303 in sequence, the vehicle control unit 301 controls the first three-phase alternating current motor 306, the first motor controller 305, the second three-phase alternating current motor 304 and the second motor controller 303 to work so as to heat the cooling liquid, and then when the cooling liquid flows through the power battery, the temperature of the power battery is increased.

Further, as shown in fig. 15, the three-phase ac motor 102 includes a motor shaft 125a, a stator assembly 127a, and a motor housing 123a, the motor shaft 125a is connected to the stator assembly 127a and the bearing seat 124a, the stator assembly 127a is disposed in the motor housing 123a, the motor housing 123a is provided with a heat exchange medium inlet 121a and a heat exchange medium outlet 126a through which the heat exchange medium 122a flows in and out, a heat exchange medium channel is disposed between the motor housing 123a and the stator assembly 127a, and the heat exchange medium channel is connected to the heat exchange medium inlet 121a and the heat exchange medium outlet 126 a.

The heat exchange medium channel may be provided between the motor housing 123a and the stator assembly 127a, and the heat exchange medium channel spirally surrounding the stator assembly 127a is provided in the motor housing 123 a.

According to the three-phase alternating current motor, the heat exchange medium channel is arranged between the motor shell 123a and the stator assembly 127a and is connected with the heat exchange medium inlet 121a and the heat exchange medium outlet 126a, so that heat generated by the motor can be effectively absorbed by heat exchange medium in the heat exchange medium channel, the channel does not need to be arranged inside the motor shaft 125a or the stator assembly 127a, the structural influence on the motor is small, the implementation mode is simple, and the cost is low.

The device comprises a power supply module, a three-phase inverter, a stator assembly, a battery cooling circuit, a stator assembly, a battery cooling circuit and a battery, wherein the three-phase inverter is controlled to enable the power supply module to alternately perform a charging process of a three-phase coil and a discharging process of the three-phase coil, so that the three-phase inverter and a three-phase alternating current motor heat a heat exchange medium flowing through at least one of the three-phase inverter and the three-phase alternating current motor through the electric driving cooling circuit, the heat exchange medium flows into a heat exchange medium inlet of the three-phase alternating current motor, the stator assembly heats the heat exchange medium in a heat exchange medium pipeline, and when the heated heat exchange medium flows through the battery cooling circuit to be heated, the temperature of the component to be heated is increased.

The application provides a vehicle, draws forth N line in three-phase AC motor, and then constitutes different return circuits with power battery and three-phase inverter, provides the heat source through inside three-phase coil of three-phase AC motor, the inside device that generates heat of three-phase inverter, the heating coolant liquid back realizes the heating to power battery through former cooling circuit, need not use the engine or increase heating device just can realize promoting power battery's temperature, and heating efficiency is high, power battery temperature risees soon.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims

1. A motor control circuit is characterized by comprising a switch module, a three-phase inverter, a three-phase alternating current motor, an energy storage module and a control module, wherein the motor control circuit is connected to a power supply module through the switch module, the first end of the three-phase inverter is connected with the positive end of the power supply module, the second end of the three-phase inverter is connected with the negative end of the power supply module, a three-phase coil of the three-phase alternating current motor is connected with a three-phase bridge arm of the three-phase inverter, the first end of the energy storage module is connected with the switch module and the three-phase inverter, the second end of the energy storage module is connected with a common junction of the three-phase coil of the three-phase alternating current motor, and the control module is connected with the switch module, the three-phase inverter, the three-phase alternating current motor and the energy storage module;

when the control module acquires that a part to be heated needs to be heated, the switch module is controlled to be switched on and controlled, the energy storage module is in a working state, and the three-phase inverter is controlled to receive the charging process of the energy storage module and the three-phase coil of the three-phase alternating current motor and the discharging process of the energy storage module and the three-phase coil of the three-phase alternating current motor are alternately performed, so that the energy storage module, the three-phase inverter and the three-phase alternating current motor heat the heat exchange medium flowing through at least one heat exchange medium pipeline in the energy storage module, the three-phase inverter and the three-phase alternating current motor.

2. The motor control circuit of claim 1 wherein said power module, said switching module, said energy storage module, said three-phase ac motor, and said three-phase inverter form a first charging loop, and said three-phase ac motor, said three-phase inverter, and said energy storage module form a discharging loop;

the control module controls the three-phase inverter to enable the first charging loop and the discharging loop to be conducted alternately, so that the charging process of the energy storage module and the three-phase coil and the discharging process of the energy storage module and the three-phase coil are conducted alternately by the power supply module.

3. The motor control circuit of claim 2 wherein said power module is a power battery and said switch module is a first switch module; or, the power supply module is an external power supply module, and the switch module is a second switch module.

4. The motor control circuit of claim 1, wherein the energy storage module comprises an energy storage device and a first switching device connected in series, the first end of the energy storage module is connected to the first end of the three-phase inverter, or the first end of the energy storage module is connected to the second end of the three-phase inverter, and the control module controls the first switching device to be turned on to control the energy storage module to be in an operating state.

5. The motor control circuit according to claim 1, wherein the energy storage module includes an energy storage device, a first switching device and a sixth switching device, a connection terminal of the sixth switching device is connected in series with the energy storage device and the first switching device, a first gate terminal of the sixth switching device is connected to the first terminal of the three-phase inverter, a second gate terminal of the sixth switching device is connected to the second terminal of the three-phase inverter, the control module controls the connection terminal of the sixth switching device to be connected to the first gate terminal or the second gate terminal, and the control module further controls the first switching device to be turned on to control the energy storage module to be in the working state.

6. The motor control circuit according to any one of claims 1 to 5, wherein the three-phase inverter includes three-phase legs, each of the three-phase legs includes two power switching units connected in series, and three-phase coils of the three-phase ac motor are respectively connected to connection points of the two power switching units of each of the three-phase legs; the control module obtains the bridge arm conduction number of the three-phase inverter according to the power to be heated and controls the corresponding number of bridge arms to work according to the bridge arm conduction number.

7. The motor control circuit according to claim 6, wherein the control module determines that the number of bridge arms of the three-phase inverter is 1 when the power to be heated is smaller than a first preset power, and controls any one of the three-phase bridge arms to operate or the three-phase bridge arms to operate by switching in turn.

8. The motor control circuit according to claim 7, wherein the control module determines that the number of bridge arms of the three-phase inverter that are connected is 2 when the power to be heated is not less than a first preset power and less than a second preset power, and controls any 2-phase bridge arms of the three-phase bridge arms to operate or three two-phase bridge arms of the three-phase bridge arms to operate in sequence, wherein the three-phase inverter includes an a-phase bridge arm, a B-phase bridge arm, and a C-phase bridge arm, the first two-phase bridge arm includes an a-phase bridge arm and a B-phase bridge arm, the second two-phase bridge arm includes an a-phase bridge arm and a C-phase bridge arm, and the first three-phase bridge arm includes a B-phase bridge arm and a C-phase bridge arm.

9. The motor control circuit of claim 8 wherein the phases of the PWM control signals sent by the control module to the two phase legs are 180 degrees apart.

10. The motor control circuit according to claim 8, wherein the control module determines that the number of bridge arms of the three-phase inverter is 3 when the power to be heated is not less than a second preset power, and controls the three-phase bridge arms to operate simultaneously.

11. The motor control circuit of claim 10 wherein said control module sends PWM control signals of the same phase to said three phase legs;

or the control module sends PWM control signals with different phases to the three-phase bridge arms, wherein the phase difference between the PWM control signal of one phase of bridge arm and the PWM control signal of the other two phase of bridge arm is 60 degrees and-60 degrees respectively.

12. The motor control circuit of claim 10 wherein the control module obtains the current value of each phase of the bridge arms when the three phase bridge arms are operating simultaneously and adjusts the control signal of each phase of the bridge arms to keep the average current value of the three phase bridge arms within a predetermined current range.

13. The motor control circuit of claim 6, wherein the control module obtains a current value of each phase of the bridge arms when the three phase bridge arms are simultaneously operated, and adjusts the control signal of each phase of the bridge arms to enable the current values of the three phase bridge arms to be not completely the same and the current difference value of each two phase of the bridge arms to be smaller than a preset current threshold value.

14. A vehicle characterized by further comprising the motor control circuit of any one of claims 1 to 13.

15. The vehicle of claim 14, wherein the three-phase ac motor includes a motor shaft, a stator assembly, and a motor housing, the stator assembly is coupled to the motor shaft, the stator assembly is disposed in the motor housing, the motor housing has a heat exchange medium inlet and a heat exchange medium outlet, a heat exchange medium passage is disposed between the motor housing and the stator assembly, and the heat exchange medium passage is coupled to the heat exchange medium inlet and the heat exchange medium outlet.

16. A method for heating a power battery, using the motor control circuit according to any one of claims 1 to 13, the method comprising: